As is known, virtually all residential homes utilize electrical power received from a utility company. Typically, utility companies have an excellent record of providing uninterrupted or infrequently interrupted power to their customers at proper voltage levels and line frequency. However, due to the increasing demand for power, power outages have become more frequent. While power outages usually last only for a short duration, an extended power outage may cause more than simple aggravation for customers of the utility. A power outage may render a homeowner's appliances, such as the sump pump, refrigerator or freezer inoperable. If a power outage occurs during a rainstorm, the failure of the sump pump to operate may result in the flooding of the homeowner's basement.
In order to combat these occasional disruptions in service, many residential customers of the utility companies have equipped their homes with stand-by electrical generator systems. These stand-by electrical generator systems include internal combustion engines that drive electrical generators. If the commercial power from the utility company fails, the internal combustion engine of the stand-by electrical generator system is automatically started causing the electrical generator to generate electrical power. When the electrical power generated by the electrical generator reaches the proper voltage and frequency desired by the customer, a transfer mechanism transfers the load imposed by the homeowner from the commercial power lines to the electrical generator.
Typically, the transfer mechanism incorporates switches that isolate the electrical power supplied by the utility company from the generator. In a residential application, the switches are flipped either manually or automatically between the utility source and the generator in order to provide power to the electrical system of the home. These prior art transfer mechanisms often require a homeowner to transfer the entire electrical system of the home onto the generator. Such an arrangement does not provide the homeowner with the ability to decide which circuits of the home's electrical system are to be powered. It can be appreciated that the demands of the entire electrical system of the home can be quite significant. As a result, the generator must be of sufficient size to power the entire electrical system of the home. This, in turn, increases the overall cost of the stand-by electrical generator system for the homeowner. Further, prior stand-by electrical generator systems require that the transfer mechanism to be interconnected to the utility source, the generator and the electrical system of the home. This usually requires the homeowner to employ an electrical contractor to make the necessary connections. Once again, the hiring of an electrical contractor increases the overall cost to the homeowner for a stand-by electrical generator system.
Therefore, it is a primary object and feature of the present invention to provide a transfer mechanism that transfers the electrical power supplied to essential devices within a residential home between a utility source and stand-by electrical generator.
It is a further object and feature of the present invention to provide a transfer mechanism that automatically transfers the electrical power supplied to essential devices within a residential home from a utility source to a stand-by electrical generator in response to a power outage.
It is a still further object and feature of the present invention to provide a transfer mechanism for transferring the electrical power supplied to essential devices within a residential home between a utility source and a stand-by electrical generator that may be simply and easily installed by a homeowner.
In accordance with the present invention, a transfer switch is provided for transferring the supply of electrical power to a load between a utility source and a generator that generates electrical power when started. The transfer switch includes a transfer relay having a utility input, generator input, an output and a coil operatively connected to the generator. The output of the transfer relay is selectively connected to one of the utility input and the generator input in response to the application of electrical power to the coil by the generator. A power cord interconnects the utility input of the transfer relay to the utility source. The power cord has a first end terminating in an electrical plug receivable within an electrical outlet electrically connected to the utility source and a second end electrically connected to the utility input of the transfer relay. A generator cord electrically connects the generator to the generator input of the relay. A first duplex outlet is electrically connected to the output of the relay. The outlet is adapted for receiving an electrical plug for the load therein.
The transfer switch may also include a second duplex outlet electrically connected to the generator. The second duplex outlet is adapted for receiving the electrical plug for the load therein. A manual exercise switch connectable to the generator may also be provided. The manual exercise switch is movable between a first non-actuated position and a second actuated position for starting the generator. A generator control structure is operatively connected to the utility source and to the generator. The generator control structure includes a generator relay having a first contact connected to the generator, a second contact connected to the generator and a coil connected to the utility source. The generator relay is movable between an open arrangement wherein the first and second contacts are isolated from each other and a closed arrangement wherein the first and second contacts are electrically coupled in response to the absence of electrical power on the coil by the utility source. The generator control structure may also include a starting relay having a first contact connected to the generator, a second contact connected to the coil of the transfer relay and a coil connected to the utility source. The starting relay is movable between an open arrangement wherein the first and second contacts are isolated from each other and a closed arrangement wherein the first and second contacts are electrically coupled in response to the absence of electrical power on the coil by the utility source.
The transfer switch may also include a utility display device connectable to the utility source. The utility display device generates a visual display in response to the application of electrical power by the utility source. Similarly, a generator display device is connected to the generator source. The generator display device generates a visual display in response to the application of electrical power by the generator.
In accordance with the present invention, a transfer switch is provided for transferring electrical power to a load between a utility source and a generator that generates electrical power when started. The transfer switch includes the transfer relay having a utility input, generator input, an output, and a coil operatively connected to the generator. The output is selectively connected to one of the utility input and the generator input in response to the application of electrical power on the coil by the generator. The transfer switch also includes a generator relay having a first contact connected to the generator, a second contact connected to the generator and a coil connected to the utility source. The generator relay is movable between an open arrangement wherein the first and second contacts are isolated from each other and a closed arrangement wherein the first and second contacts are electrically coupled in response to the absence of electrical power on the coil by the utility source. A first duplex outlet is electrically connected to the output of the transfer relay. The first duplex outlet is adapted for receiving an electrical plug for the load therein.
A power cord interconnects the utility input of the transfer relay to the utility source. The power cord has a first end terminating at an electrical plug that is receivable within an electrical outlet electrically connected to the utility source and a second end electrically connected to the utility input of the transfer relay. A second duplex outlet is electrically connected to the generator. The second duplex outlet is adapted for receiving the electrical plug for the load therein. A manual exercise switch is also connectable to the generator. The manual exercise switch is movable between a first non-actuated position and a second actuated position for starting the generator.
The transfer switch may also include a starting relay having a first contact connected to the generator, a second contact connected to the coil of the transfer relay and a coil connected to the utility source. The starting relay is movable between an open arrangement wherein the first and second contacts are isolated from each other and a closed arrangement wherein the first and second contacts are electrically coupled in response to the absence of electrical power on the coil of the starting realy by the utility source. A utility display device is also connected to the utility source. The utility display device generates a visual signal in response to the application of electrical power by the utility source. In addition, a generator display device is connected to the generator source. The generator display device generates a visual display in response to the application of electrical power by the generator.
In accordance with a still further aspect of the present invention, a transfer switch is provided for transferring the supply of electrical power to a load between a utility source and a generator that generates electrical power when started. The transfer switch includes a transfer relay having a utility input, a generator input, an output, and a coil operatively connected to the generator. The output of the transfer relay is selectively connected to one of the utility input and the generator input in response to the application of electrical power upon the generator. A power cord has a first end terminating at an electrical plug that is receivable within the electrical outlet electrically connected to the utility source and a second end electrically connected to the utility input of the transfer relay. A first duplex outlet is electrically connected to the output of the transfer relay. The first duplex outlet is adapted for receiving an electrical plug for the load therein. The second duplex outlet is electrically connected to the generator. The second duplex outlet is also adapted for receiving the electrical plug for the load therein.
The transfer switch may also include a generator relay having a first contact connected to the generator, a second contact connected to the generator and a coil connected to the utility source. The generator relay is movable between an open arrangement wherein the first and second contacts are isolated from each other and a closed arrangement wherein the first and second contacts are electrically coupled in response to the absence of electrical power on the coil by the utility source. A manual exercise switch is connected to the generator. The manual exercise switch is movable between the first non-actuated position and a second actuated position for starting the generator. The transfer switch also includes a starting relay having a first contact connected to the generator, a second contact connected to the coil of the transfer relay and a coil connected to the utility source. The starting relay is movable between an open arrangement wherein the first and second contacts are isolated from each other and a closed arrangement wherein the first and second contacts are electrically coupled in response to the absence of electrical power on the coil by the utility source. A utility display device is connectable to the utility source. The utility display device generates a visual display in response to the application of electrical power by the utility source. A generator display device is connectable to the generator. The generator display device generates visual display in response to application of electrical power by the generator.